纤维素纳米晶体薄膜的制备与表征

讨论了两种新型纤维素纳米晶体(Cellulose nanocrystal,CNC)薄膜的制备方法:浸没法和旋涂法,并利用红外反射吸收光谱(Infrared reflection absorption spectroscopy,IRRAS)和原子力显微镜(Atomic force microscopy,AFM)对其进行表征。AFM高度图显示两种工艺制备的CNC薄膜均由棒状的CNC纳米颗粒交错叠加而成。实验结果显示,旋涂法制备的薄膜更加光滑,粗糙度RMS约为2.7 nm。由于带电颗粒间斥力的存在,浸没法制备的CNC膜厚度最大约为15 nm,而旋涂法可以得到更厚的CNC薄膜,其厚度可达50 nm以上。研究CNC悬浮液浓度与旋涂法CNC膜厚之间的关系后发现,可以通过改变CNC溶液的浓度对薄膜厚度进行控制。IRRAS结果也证实随着CNC悬浮液浓度的增加,旋涂薄膜的厚度随之增加。     

All-reflective optical system design for extreme ultraviolet lithography

All-reflective optical systems,due to their material absorption and low refractive index,are used to create the most suitable devices in extreme ultraviolet lithography （EUVL）.In this letter,we present a design for an all-reflective lithographic projection lens.We also discuss its design idea and structural system.After analysis of the four-mirror optical system,the initial structural parameters are determined,the optical system is optimized,and the tolerances of the system are analyzed.We also show the implementation of optimal layout and desired imaging performance.     

Study of a narrowband reflection filter with multi-channels

Reflection filters have various applications in optical communication and other systems.In this letter,we propose a narrowband high-reflection filter composed of dielectric and metallic layers,in which an optimized filter combined with an admittance-matching layer with broad stop band is achieved.The structure can be expressed as Sub ｜ （HL）13H2L（HL）313Cr0.84H ｜ air,with full-width at half-maximum （FWHM） bandwidth of 2.5 nm.Based on this structure,reflection filters with multi-peaks are presented,and the law of distribution of peak positions is drawn.     

The transient scattering mechanism of dipole array with reflector

The transient backscattering mechanisms of a dipole array with reflector have been investigated from different aspects： time-domain, frequency-domain, and combined time-frequency domain, using 4 × 8 dipole arrays with reflector as an example. The data of scattering from the arrays under the incidence of Gaussian pulses are obtained by finite differential time domain method. The influences of the array structural parameters, incident wave parameters, and incident angles on the waveforms, spectrum, and time-frequency representations of the backscattered fields of the arrays are analysed and conclusions are drawn. From these characteristics and conclusions, it is possible to deduce the array structure inversely from the backscattered field.     

三维轴对称折叠腔CO2激光器的位相锁定

在一新型三维轴对称腔CO2激光器的基础上提出了一种对此激光器位相锁定的方法。通过在输出镜后放置一具有反射和整形作用的凹凸镜，让作为输出注入光束的谐振腔优先起振。此腔输出的光束到达凹凸镜时被其反射。利用重新定义光斑半径的方法，证明此光束能够覆盖其他放电管输出的光束，根据几何光学，此光束能反射进入各个放电管。然后利用光子简并度的概念证明了反射光束能够控制腔内的本征模式，并且数值分析了注入锁定后腔内模式匹配。在反射注入锁定的情况下，给出了数值计算的光强输出及其模拟，结果证明经位相锁定后，激光器输出光束的质量有了很大的提高。     

金属材料再加载“准弹性”响应的实验验证

从连续介质力学理论看，当材料发生屈服后处于上屈服面，对处于上屈服面的材料进行再加载，将沿着上屈服面，依然发生塑性流动，不可能存在弹性响应。Asay则认为冲击压缩后的材料并非处于上屈服面，由此对处于冲击压缩态的材料进行卸载或再加载，可以观测到弹-塑性转变。国内部分人认为，实验观测到的弹性响应可能是LiF窗口（其冲击阻抗低于Al或其他高阻抗样品的冲击阻抗）反射的稀疏波所致。为了澄清对上述问题的观点，通过低阻抗样品的冲击实验，在消除冲击波在样品／窗口界面反射的稀疏波干扰的情况下，     

ICF瞄准定位系统的设计

将"神光Ⅱ"装置的原瞄准定位系统改为全反射式,可以用各波长的三倍频激光打靶.本文介绍一个双球面的反射系统的光学设计和测试结果.     

长余辉发光材料的紫外-可见反射光谱测定

用“湿法”制备了长余辉发光材料,原料通过水溶液液相分子水平上的均匀混合,利用金属硝酸盐和有机还原剂在较低的温度下发生氧化还原燃烧反应,一步快速生成产品。加热起燃温度低至500℃,反应时间短,所制得的产品成份均匀,晶粒小,外观呈蓬松状态,易研磨粉碎,粉体表观密度小。以紫外－可见分光光度计测定分析了所制备样品在蓄光前后的反射光谱特征并作了探讨。结果表明,除表观密度外,“显法”与“干法”制备的长余辉发光材料的主要性质相同,紫外－可见反射光谱可以准确描述长余辉发光材料的紫外－可见光谱性能特征。